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Federal Noxious Weed
TDA Noxious Weed TPWD Prohibited Exotic Species Invasive Plant Atlas of the USNOTE:
means species is on that list.
Panicum repens
Torpedograss
Synonym(s): Panicum gouinii
Family: Poaceae (Grass Family)
Duration and Habit: Perennial Grass/Grasslike
Photographer: John D. Byrd, Bugwood.org
Source: Mississippi State University
Description
Torpedograss is a perennial grass that can reach up to 3 ft. (1 m) tall. Plants have long, creeping rhizomes with sharp-pointed (torpedo-like) tips. Leaves are linear, flat or folded, 10 in. (26 cm) long, 0.3 in. (5.3 mm) wide with a whitish, waxy covering. Leaf sheaths can be smooth or hairy and the ligule is membranous with short hairs. Flowering occurs nearly year round. Florets develop in branched, open inflorescences that are 2.8-7.1 in. (7-18 cm) long and are yellow or straw in coloration.
Native Lookalikes: Currently no information available here yet, or there are no native Texas species that could be confused with Torpedograss.
Ecological Threat: Torpedograss is highly resilient and can survive during extreme drought conditions but prefers moist soil. Once established this grass is very difficult to eradicate. It quickly forms monocultures that displace native vegetation, particularly in or near shallow waters
Biology & Spread: Propagation occurs primarily vegetatively by rhizome growth but seeds may also be dispersed by human activity or water. Torpedo grass flowers nearly year-round, but it is variable in its seed abundance and viability.
History: Torpedograss was first documented in the US in 1876 in Alabama but it is believed to have been introduced to the United States earlier in Louisiana. This type of grass was used for agriculture because cattle did not trample it as easily due to its structure.
U.S. Habitat: This species can occur in a wide variety of habitats. Plants are usually found in damp soils of riparian zones, but can also be found in pastures and on sand dunes. Plants are salt
Distribution
U.S. Nativity: Introduced to U.S.
Native Origin: Africa and Eurasia
U.S. Present: AL, CA, FL, HI, LA, MS, NC, SC, TX
Distribution in Texas: Most reports from southeast Texas with some from the Dallas area.
Mapping
Invaders of Texas Map: Panicum repens
EDDMapS: Panicum repens
USDA Plants Texas County Map: Panicum repens
Invaders of Texas Observations
List All Observations of Panicum repens reported by Citizen Scientists
Native Alternatives
Management
Preventative: Control can be accomplished to some degree by preventing the spread and fragmentation of rhizomes. This can be very difficult because if even a tiny fragment of rhizome remains, it will reestablish itself. Control of infestations near waterways will prevent long-range spread via water and this should be a priority.
Cultural: Weeds such as torpedograss generally invade open or disturbed areas following a burn, clearing mowing, etc., so these areas are particularly vulnerable to invasion. Therefore, a healthy ecosystem with high species diversity may help to deter infestation.
Mechanical and Biological: Currently, there are no available biological control agents for torpedograss. There are limited agents being researched, and Dr. Charudattan at the University of Florida has been evaluating a species of fungus. Torpedo grass is very palatable for cows and goats, and grazing may be integrated in an overall management scheme. If mowing or tillage is used, care must be taken to prevent transport of rhizome or stolon fragments.
Chemical: Herbicide can be effective for controlling torpedograss in some situations. Glyphosate has proven effective for treating torpedograss above the water line but ineffective on plants growing in the water.
Text References
Center for Aquatic and Invasive Plants. 2009. Panicum repens: Torpedo Grass. University of Florida, IFAS.
Florida Exotic Pest and Plant Council. Panicum repens: torpedo grass. Accessed February 2009: http://www.fleppc.org/ID_book/Panicum%20repens.pdf.
Online Resources
Miller, J.H. 2003. Nonnative invasive plants of southern forests: a field guide for identification and control. Gen. Tech. Rep. SRS-62. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 93 pp (USDA SRS).
Bugwood Network. Bugwood.org
Search Online
Google Search: Panicum repens
Google Images: Panicum repens
NatureServe Explorer: Panicum repens
USDA Plants: Panicum repens
Invasive Plant Atlas of the United States: Panicum repens
Bugwood Network Images: Panicum repens
